Re: [Qemu-devel] [PATCH v3 4/8] qemu-img: potential Null pointer deref in img_commit()

[John Snow <jsnow@redhat.com>]

On 08/31/2018 02:16 PM, Liam Merwick wrote:
> The function block_job_get() may return NULL so before dereferencing
> the 'job' pointer in img_commit() it should be checked.
> 
> Signed-off-by: Liam Merwick <Liam.Merwick@oracle.com>
> Reviewed-by: Darren Kenny <Darren.Kenny@oracle.com>
> Reviewed-by: Mark Kanda <Mark.Kanda@oracle.com>

Reviewed-by: John Snow <jsnow@redhat.com>

> ---
>  qemu-img.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/qemu-img.c b/qemu-img.c
> index b12f4cd19b0a..51fe09bd08ed 100644
> --- a/qemu-img.c
> +++ b/qemu-img.c
> @@ -1029,6 +1029,9 @@ static int img_commit(int argc, char **argv)
>      }
>  
>      job = block_job_get("commit");
> +    if (job == NULL) {
> +        goto unref_backing;
> +    }
>      run_block_job(job, &local_err);
>      if (local_err) {
>          goto unref_backing;
>